FORTRAN 90: Functions, Modules, and Subroutines (pdf format)

INTENT(IN)
• When a function is referenced, the values of the actual arguments are
passed to the function
– Values are used in the calculation, but should not change during execution of the
function.
• INTENT(IN) protects the corresponding actual argument by ensuring that
the value of the formal argument cannot be changed during function
execution.
• If not used, the value of the formal argument may be changed in the
function and the value of the corresponding actual argument will also
change.
• Number and type of actual arguments must agree with the number and type
of formal arguments.
• NOTE: Local identifiers can be defined within the function, just as in the
main program.